[jira] [Commented] (HIVE-2019) Implement NOW() UDF
[ https://issues.apache.org/jira/browse/HIVE-2019?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13635327#comment-13635327 ] Eric Hanson commented on HIVE-2019: --- Agreed, especially with the phrase right before executing the query. The timestamp should be gotten once at query execution startup time, not compile time. Although these two steps are pretty much the same in Hive now, someday there could be a plan cache, so a cached NOW() result would get stale. Or, if a compilation takes a long time for some reason, NOW() could get stale. This is how it is done in one commercial DBMS that I know. If there are multiple different flavors of date and time functions, they should all be based off the same internal hi-resolution timestamp. That way they would all be consistent within one query execution if multiple functions are used, say DATE(), NOW() etc. in the same query. Implement NOW() UDF --- Key: HIVE-2019 URL: https://issues.apache.org/jira/browse/HIVE-2019 Project: Hive Issue Type: New Feature Components: UDF Reporter: Carl Steinbach Assignee: Priyadarshini Attachments: HIVE-2019.patch Reference: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_now -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (HIVE-2019) Implement NOW() UDF
[ https://issues.apache.org/jira/browse/HIVE-2019?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13634112#comment-13634112 ] Zhuoluo (Clark) Yang commented on HIVE-2019: If we use now() for filters, the result will be uncertain. Because if a Map Task is scheduled first, the now() of this map task is earlier, if this task is scheduled later, the now() of this map task is later. In our production environment, a lot of hive tasks are scheduled at mid night, the now() of the Tasks may cross a day for the scheduling orders. I think it is necessary to add a kind of UDF called UDCF. (User Defined Client Functions). if we get the client side now() and make it a constant during compile time, it will be no such problems. Implement NOW() UDF --- Key: HIVE-2019 URL: https://issues.apache.org/jira/browse/HIVE-2019 Project: Hive Issue Type: New Feature Components: UDF Reporter: Carl Steinbach Assignee: Priyadarshini Attachments: HIVE-2019.patch Reference: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_now -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (HIVE-2019) Implement NOW() UDF
[ https://issues.apache.org/jira/browse/HIVE-2019?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13634121#comment-13634121 ] Zhuoluo (Clark) Yang commented on HIVE-2019: [~priyadarshini] I think the patch is a little bit simple, and should consider distributed situation. I think a better way is to fold the NOW() into a constant during compile time. Implement NOW() UDF --- Key: HIVE-2019 URL: https://issues.apache.org/jira/browse/HIVE-2019 Project: Hive Issue Type: New Feature Components: UDF Reporter: Carl Steinbach Assignee: Priyadarshini Attachments: HIVE-2019.patch Reference: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_now -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (HIVE-2019) Implement NOW() UDF
[ https://issues.apache.org/jira/browse/HIVE-2019?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13634148#comment-13634148 ] Edward Capriolo commented on HIVE-2019: --- UDFs have a deterministic annotation you should explore. Implement NOW() UDF --- Key: HIVE-2019 URL: https://issues.apache.org/jira/browse/HIVE-2019 Project: Hive Issue Type: New Feature Components: UDF Reporter: Carl Steinbach Assignee: Priyadarshini Attachments: HIVE-2019.patch Reference: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_now -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (HIVE-2019) Implement NOW() UDF
[ https://issues.apache.org/jira/browse/HIVE-2019?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13634176#comment-13634176 ] Zhuoluo (Clark) Yang commented on HIVE-2019: Actually, NOW() is not a non-deterministic UDF like rand(), for every time you call it, it returns different answers. Is HIVE-746 a related JIRA issue? Implement NOW() UDF --- Key: HIVE-2019 URL: https://issues.apache.org/jira/browse/HIVE-2019 Project: Hive Issue Type: New Feature Components: UDF Reporter: Carl Steinbach Assignee: Priyadarshini Attachments: HIVE-2019.patch Reference: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_now -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (HIVE-2019) Implement NOW() UDF
[ https://issues.apache.org/jira/browse/HIVE-2019?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13634805#comment-13634805 ] Navis commented on HIVE-2019: - Agreed. NOW() should be replaced with a constant right before executing the query. It's non-deterministic in compile time but can be regarded as deterministic in runtime. Implement NOW() UDF --- Key: HIVE-2019 URL: https://issues.apache.org/jira/browse/HIVE-2019 Project: Hive Issue Type: New Feature Components: UDF Reporter: Carl Steinbach Assignee: Priyadarshini Attachments: HIVE-2019.patch Reference: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_now -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (HIVE-2019) Implement NOW() UDF
[ https://issues.apache.org/jira/browse/HIVE-2019?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13170798#comment-13170798 ] Priyadarshini commented on HIVE-2019: - I am working on this. I have few doubts to clarify with respect to this. select now(),now() from tname The above query shud return the same time in both ofthe columns ? I find that in the reference link it does it. One more doubt is if we want of this format, select now()+0 from tname i.e adding some integers to the now() function, it shuould be possible that now() fucntion should take argument like which format user want. So for operations for adding some integer to now() funciton, we may hav to pass the format also Implement NOW() UDF --- Key: HIVE-2019 URL: https://issues.apache.org/jira/browse/HIVE-2019 Project: Hive Issue Type: New Feature Components: UDF Reporter: Carl Steinbach Reference: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_now -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (HIVE-2019) Implement NOW() UDF
[ https://issues.apache.org/jira/browse/HIVE-2019?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13170801#comment-13170801 ] Priyadarshini commented on HIVE-2019: - I will implement 2 possible uses One with default - now() Other that takes a format as an argument and supports adding integer to it i.e seelct now(format string) + 1 from tname Implement NOW() UDF --- Key: HIVE-2019 URL: https://issues.apache.org/jira/browse/HIVE-2019 Project: Hive Issue Type: New Feature Components: UDF Reporter: Carl Steinbach Reference: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_now -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
